Lignin-Based Composite Carbon Nanofibers

Lignin, the second most abundant biopolymer on earth, has the potential as a low-cost and renewable precursor for carbon fibers. By creating lignin-based carbon nanofibers for lightweight structural composites for automobiles and functional applications such as electromagnetic shields, the value of lignin will be enhanced. In this chapter, we present the feasibility of producing carbon nanofibers from lignin by electrospinning and heat treatment, as well as reviewing the potential applications. The morphological, mechanical, and electromagnetic properties of the lignin-based carbon nanofibers are presented. The strength of lignin random nanofiber mats was significantly improved after carbonization and alignment. By doping the lignin polymer with carbon nanotubes and functional nanoparticles such as magnetite, it was possible to improve the strength and introduce electromagnetic functionality to the lignin nanofiber assemblies. These encouraging results demonstrate the potential of lignin-based composite carbon nanofibers as a unique engineering material, thus establishing a pathway for adding value to the abundantly available natural polymer, lignin.